Is changing a cold water tank a diy job?

[Mrxman]

I am about to move into a new house. Cold water tank has no lid and no insulation. Was thinking it might be best to change
it to a new round one. I've done some bathroom plumbing before.

Q1: is this a managable diy job?
Q2: The overflow pipe seems to be made of brown plastic. Never seen that before. Any idea what type it could be?
Q3: I am tempted to change to combi boiler but given the boiler is from 2018 vaillant ecotec and located in an outhouse, moving it upstairs could be expensive. Are cold water tanks safe to use generally?

Many thanks

 

[CountryFan]

It can be a DIY job, but beware that existing could contain asbestos

 

[foxhole]

Easy enough to drop a sheet of ply or rigid insulation on for a lid and insulate .

 

[Mrxman]

It can be a DIY job, but beware that existing could contain asbestos

It's a plastic tank. Looks like a round polytank but just a bit older

 

[Mrxman]

Easy enough to drop a sheet of ply or rigid insulation on for a lid and insulate .

Plywood as a lid? I am just wondering about condensation in the loft. It would be cheaper of course but is it as effective as a proper lid?

 

[CountryFan]

Plywood as a lid? I am just wondering about condensation in the loft. It would be cheaper of course but is it as effective as a proper lid?

Wouldn’t be to water regulations.

 

[foxhole]

Have seen all kinds of material used as a tank lid .Dont drink the water .

 

[mikehammer69]

I am about to move into a new house. Cold water tank has no lid and no insulation. Was thinking it might be best to change
it to a new round one. I've done some bathroom plumbing before.

Q1: is this a managable diy job?
Q2: The overflow pipe seems to be made of brown plastic. Never seen that before. Any idea what type it could be?
Q3: I am tempted to change to combi boiler but given the boiler is from 2018 vaillant ecotec and located in an outhouse, moving it upstairs could be expensive. Are cold water tanks safe to use generally?

Many thanks

Can a lid not be sourced for it?

The way I'd be looking at it . DIY changing of a water tank would be low on my list of priorities and carries some risk

 

[Hugh Jaleak]

Pretty easy to DIY if you're confident with Plumbing. Get a new Cistern, (Tanks are sealed vessels, Cisterns are open), of the required size, and Byelaw 30 kit to suit. Brown Overflow, seem to recall Osma had a stage of using brown Plastic in the 70's, it could date from then! Ideally I'd say replace, if not then compression fittings are available to join new to old.

After removing existing Cistern, ensure the base is adequate to support the weight of the new Cistern. 1 litre of water weighs 1kg, so if you have a 40/25 Gallon Cistern with the 25 Gallons of water in it, that's still over 110 kg to support.

Site Cistern as required then work out where pipe entries are going to be, cut with suitable Hole Saw, fit Tank rolleyes Connectors, and couple up to original pipework. If a Mixer Shower is fitted, then ensure cold supply to this is taken from below the feed to the Hot Water Cylinder to prevent scalding in the event of the Cistern being emptied.


Once connections are made, restore supply, fill Cistern and check for leaks. When happy all is watertight, fit Lid and Insulation as required.

 

[danfre]

Base has to be a specific size with overhang, pretty sure it should be 18mm plywood as well

 

[Justin Passing]

Do have a google for diagrams on the bits and pieces, which aren't obvious. Many of them I wouldn't follow exactly for one reason or another!

This one is from the Regs, for two tanks(/cisterns!) - obviously leave out the extras, & header arrangement. You need TWO outlet valves for H & C (C lower, as above) unless you have a separate feed to a WC, say as well.
This DOES show how the overflow fitting hangs, and using quarter turn valves, which I would, but only decent quality ones like Conex, not B&Q's cheapest.
You wouldn't use the separate cover - just make sure the plummin doesn't stop you taking the lid off.

It does not show that you have to put the VENT pipe which I added in red from eg a HW cylinder, through the top, which should also be an insect-sealed connection - ie it needs a fitting not just a hole.
Look at several illustrations.

Then there's the insulation of course. Google that. All in there are several things to get right, including the others' comments here.
Oh - put a gap in the insulation underneath to help stop it freezing - the house can warm it a little.
Don't use a BS 1212 part ONE float valve, you need a part TWO or better.

 

[Mottie]

I am tempted to change to combi boiler but given the boiler is from 2018 vaillant ecotec and located in an outhouse, moving it upstairs could be expensive.

My mate had a combi fitted in his loft. Took so long for hot water to reach is kitchen sink, they used to either wash up in cold water or boil a kettle.

 

[Mrxman]

Can a lid not be sourced for it?

The way I'd be looking at it . DIY changing of a water tank would be low on my list of priorities and carries some risk

I can definitely source a lid but getting it to fit could be problematic. Also the tank is full of limescale and algae

 

[Mrxman]

Pretty easy to DIY if you're confident with Plumbing. Get a new Cistern, (Tanks are sealed vessels, Cisterns are open), of the required size, and Byelaw 30 kit to suit. Brown Overflow, seem to recall Osma had a stage of using brown Plastic in the 70's, it could date from then! Ideally I'd say replace, if not then compression fittings are available to join new to old.

After removing existing Cistern, ensure the base is adequate to support the weight of the new Cistern. 1 litre of water weighs 1kg, so if you have a 40/25 Gallon Cistern with the 25 Gallons of water in it, that's still over 110 kg to support.

Site Cistern as required then work out where pipe entries are going to be, cut with suitable Hole Saw, fit Tank rolleyes Connectors, and couple up to original pipework. If a Mixer Shower is fitted, then ensure cold supply to this is taken from below the feed to the Hot Water Cylinder to prevent scalding in the event of the Cistern being emptied.


Once connections are made, restore supply, fill Cistern and check for leaks. When happy all is watertight, fit Lid and Insulation as required.

Thanks for this. That’s great. The tank currently there I’d say is 50 gallon so a new piece of 18 mm plywood under the tank might be required. There’s plenty of joists support . I wouldn’t call myself a confident plumber but I usually get there and judging from your instructions it seems manageable

 

[Mrxman]

Do have a google for diagrams on the bits and pieces, which aren't obvious. Many of them I wouldn't follow exactly for one reason or another!

This one is from the Regs, for two tanks(/cisterns!) - obviously leave out the extras, & header arrangement. You need TWO outlet valves for H & C (C lower, as above) unless you have a separate feed to a WC, say as well.
This DOES show how the overflow fitting hangs, and using quarter turn valves, which I would, but only decent quality ones like Conex, not B&Q's cheapest.
You wouldn't use the separate cover - just make sure the plummin doesn't stop you taking the lid off.

It does not show that you have to put the VENT pipe which I added in red from eg a HW cylinder, through the top, which should also be an insect-sealed connection - ie it needs a fitting not just a hole.
Look at several illustrations.

View attachment 422228

Then there's the insulation of course. Google that. All in there are several things to get right, including the others' comments here.
Oh - put a gap in the insulation underneath to help stop it freezing - the house can warm it a little.
Don't use a BS 1212 part ONE float valve, you need a part TWO or better.

Great diagram. Thanks , that’s really useful. It looks a lot more pro than the setup I am looking at which has an old lead pipe pointing into tank. The plastic bylaw 30 kit that comes with a new tank is that adequate?